The Box Elder Bug, Leptocoria trivittatue (say), is a hanipterous insect belonging to the family corisidae. Although it rarely is a pest of agricultural crops, its habit of invading homes and other buildings for hibernation and to warm itself has made it an annoying household pest. It has proven to be a difficult insect to control. Only a few of the contact insecticides, useful in control of related insect pests, have given satisfactory control of the Boxelder Bug. Because it has not been considered a critical problem, it has not received detailed attention from the scientific investigators. Its close association with boxelder trees has long been recognized. Elimination of boxelder trees has often been advocated for control of this insect. However, boxelder is not its only host and, furthermore, elimination of boxelder trees is not always practical or desirable.